The current world-average of the strong coupling at the Z pole mass,
αs​(mZ2​)=0.1181±0.0013, is obtained from a comparison of
perturbative QCD calculations computed, at least, at
next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental
observables: (i) lattice QCD "data", (ii) Ï„ hadronic decays, (iii) proton
structure functions, (iv) event shapes and jet rates in e+e− collisions,
(v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p
collisions. In addition, at least 8 other αs​ extractions, usually with
a lower level of theoretical and/or experimental precision today, have been
proposed: pion, Υ, W hadronic decays; soft and hard fragmentation
functions; jets cross sections in pp, e-p and γ-p collisions; and photon
F2​ structure function in γγ collisions. These 14 αs​
determinations are reviewed, and the perspectives of reduction of their present
uncertainties are discussed.Comment: 4 pages, 2 figures. Minor changes. Version submitted to Proceedings
Moriond QCD 201